English

Harmonic projection and hypercentral extensions

Group Theory 2026-02-03 v1

Abstract

The Liouville property is a strong form of amenability, but contrary to amenability, it is not well-behaved under extensions. In this paper it is shown that, for some measures, the Liouville property is preserved by [FC-]hypercentral extensions. To this end a projection from \ell^\infty onto the space of harmonic functions is introduced.

Cite

@article{arxiv.2602.00187,
  title  = {Harmonic projection and hypercentral extensions},
  author = {Antoine Gournay},
  journal= {arXiv preprint arXiv:2602.00187},
  year   = {2026}
}

Comments

12 pages

R2 v1 2026-07-01T09:28:33.906Z